Turn off the device currently watched and turn on the device you want to operate. Does it work?
There are few devices that still output a video signal when in standby. In certain situations the Smart HDMI switch will not recognize the device as off. When so please switch manually to the correct input.
It might also be the case that (one of) the HDMI inputs does not have enough power to feed the HDMI switch. In that case connect a micro USB cable to the SV1632 to power it.
